Ocular blood flow measured with scanning laser doppler flowmeter in normals and glaucoma patients

Purpose: To compare the retinal and optic nerve head (ONH) capillary hemodynamics of the two eyes of patients with asymmetric glaucoma. Methods: Fourteen consecutive patients with POAG, NTG or pseudoexfoliative glaucoma who had asymmetric disease, with a well established visual field defect in one eye and a normal visual field in the other eye, associated with a cup-disc ratio asymmetry of at least 0.2, were evaluated with a scanning laser Doppler flowmeter (SLDF - Heidelberg Engineering, Germany). With this equipment, hemodynamic parameters of the capillary bed at the peripapillary retina and ONH (neuroretinal rim and lamina cribosa area) were measured in specific locations in both eyes. Results: The measured values, in relative units, of "flow", "volume" and "velocity" were significantly lower in the more damaged eyes compared to the contralateral eyes in the temporal neuroretinal rim (p < 0.05) and in the lamina cribosa (p < 0.03). No difference was found in the measurements performed in four areas of the peripapillary retina. Conclusions: Patients with asymmetric disease studied with the SLDF showed worse blood flow in the ONH (neuroretinal rim and lamina cribosa) in the more affected eye. These changes may precede damage or be secondary to it. The pathogenic importance of ONH blood flow abnormalities and glaucomatous damage must be further evaluated.